Clay,You mean like the way the fin and rudder departed the B-52 over colorado?An aircraft like ANY stucture will break if it is stressed past it's design limits. In their testing requirements FAA only ask for a steady single deflection of the rudder. Cyclic operation of the rudder can produce much greater loads and this is apparently what happened to the Airbus in question.It's dissappointing to see this thread turn into a Boeing verses Airbus Industries .We should concentrate on the incident and learn from it to ensure that such a terrible accident like this doesn't happen again to ANY aircraft.Cheers,Roger

G'day Douglas,>I agree. But the point I wanted to make is economics often>overrule safety, and airlines operate (and base their profit>margins) on what they can get away with. Like it or not, and>believe it or not, fatal crashes are a contingency planned for>and are considered acceptable risks. >The above may certainly apply to the way some airlines operate but NOT to the aircraft manufacturers.To give an idea of how an aircraft is designed;In straight and level flight the loading is 1g. Then the maximum anticipated flight load is calculated at 2.5g ( Boeing have arrived at this figure by years of development) . Another 50% ( factor of safety ) is then added to the maximum anticipated flight loads so that brings the loads up to 3.75g This then becomes 100% design objective. All major structures are the statically tested and MUST reach 100% design objective or better before failure occurrs.If you do the maths backwards in straight and level flight the loads on the airframe are only 26% of the design objective.>For aircraft, weight dictates success. The lighter it is, the>cheaper the operating costs. Some of the newer airplanes have>plastic screws for interior trim, and if that were the extent>of the cost-conscious measures then there wouldn't be a>problem beyond the obvious difficulty of removing and>re-installing plastic hardware without damage over the many>inspections during the aircraft's lifetime, when even quality>metal hardware needs frequent replacement. Sure; Welcome to the world of advanced composites. Weight savings are PRESENTLY due to new lightweight materials - not at the expense of structural integrity.It hasn't happened yet, BUT, if computers can be put in charge of controlling an aircraft ( a la Airbus ) then designers will definitely take a long hard look at the "factor of safety". There is a huge weight saving to be made. Aviation is an extremely conservative industry and any changes will be in very small increments>When you gut the interiors on some of these birds, there isn't>much there. Compared to older aircraft, the older airframes>are built like a tank. Food for thought if you have an>uncommanded rudder hardover at .75 Mach. If ever a rudder makes it to an uncommanded hard over (full) deflection at Mach .75 even a tank structure wouldn't help you. :-)A full commanded rudder @ that mach is only 4 degrees. ( B747 )Cheers,Roger

Douglas,>Not sure this was aimed at me.... Not at all, just a general stab. This was a tragedy that should be able to be discussed, without the "OMGAIRBUSPLASTIC", was my point. Just not a factor. Lets discuss the rudder limiter, if anything. If I had to pin the tail on the donkey, I'd do it here. The sensitivity on the A306 unit is specific to the A306, not an Airbus-wide "problem"(using that word very carefully). I really can see both sides of the story here; it does behave differently than limiter/load relief systems on other aircraft, and the differences are quite significant. I distribute blame equally here, between operator and manufacturer, for not ensuring that these differences were understood by those who needed to understand them most. You could blame Airbus for manufacturing such a system, but isn't AA equally responsible then for not properly training for it's use ?

>inputs at the airspeeds involved is doubtful, and putting a>little pressure on the pedal is tantamount to a bootful of>rudder. Little? 140 lbs force is little?Why don't you read the whole 3 pages on the subject in recent Aviation Week with all the graps showing exact sequence what F/O actually did and when he did it. And then you stop making sentences that something is "doubtful" since it actually happened. Seems like you are missing a lot of *facts*.a Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2, Omega 2.7.90 (4xAA 16xAF)

>>>> The above may certainly apply to the way some airlines operate but NOT to the aircraft manufacturers.<<<

>>>> Not at all, just a general stab.<<<

From the toll bridge vidio, It looked like the a/c was venting fluid or flames heavly right at the beginning of the decent. How could the loss of the vertical stabilizer induce that? Or did I misread the vidio?

The statement was that "no matter what, the tail should not have departed the aircraft". Emphasis on the "no matter what".He's not saying the tail coming off was the cause, just that it did come off.